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SIG Sauer P938

• moderate
• Shop tier 2
• medium confidence
• Pistol
• single action
• micro compact
• concealed carry
• thumb safety
• 1911 pattern layout

field strip ~3 min · reassembly ~4 min · detail strip ~25 min

Specifications

Model-specific safety

• The P938 is a scaled-down single-action 1911-pattern pistol with a thumb safety, intended for cocked-and-locked carry. It is not a striker pistol and it is not a DA/SA SIG — its manual of arms is the 1911’s.
• It has no grip safety, unlike a 1911. The thumb safety is the only manual safety.
• The recoil spring in this very small pistol is stiff and strongly compressed when the slide comes off.
• Carry pistols accumulate pocket lint around the firing pin channel and extractor.

Under spring tension

• Recoil spring assembly
• Hammer spring
• Magazine spring

Easily lost parts

Slide stop · Recoil spring assembly

Tools

No tools required for the field strip.

Shop difficulty

Shop tier 2 Tier 2 — moderate among pistols, for the full job: strip to the parts that get coated and put it back together working. A small 1911-pattern gun: 46 parts with a mainspring housing and pin lock, sear spring, firing-pin block, and an ambidextrous safety whose detent plunger and spring launch when the safety is pushed out. More hand work than a striker gun, less than a full-size 1911.

Parts: 46 numbered parts (13.3 Parts List with 13.2 Parts Diagram in the combined P238/P938 manual (the manual's only pistol list; .22 conversion lists omitted), complete pistol incl. magazine.), from P238 / P938 Operator's Manual (1202508-01 Rev03) — SIG SAUER, Inc., p. 62–63 sigsauer.com [3].

Bench time: about 25 min to strip, 40 min to rebuild (estimate). Slide (firing pin stop, firing pin and block, external extractor, sights, bushing) and frame (mainspring housing and pin lock, sear spring, sear, hammer, trigger, ambi safety and detent, slide stop, mag catch); rebuild longer for the safety detent and sear spring.

Small parts: 13 pins, 5 springs, 2 detents or plungers (counted from the manufacturer's parts list (one per key number unless a quantity is given))

What comes off for coating

• Slide: barrel bushing, recoil spring and guide, firing pin stop, firing pin, spring, block and spring, external extractor, pin and spring, rear sight, front sight — sight pusher
• Frame: mainspring housing, pin and pin lock, mainspring, sear spring, sear and pin, hammer and pin, ambidextrous safety, detent plunger and spring, trigger, trigger bar and pins, magazine catch/trigger bar spring, slide stop and pin, grips — punch, ziplock bag, business card / thin plastic

Special tools

• thin plastic card — Holding the safety detent plunger down while the safety is turned in
• dovetail sight pusher (or brass drift and padded vise) — Removing and refitting dovetailed sights for coating

Known pain points

• Pushing the safety out frees the safety detent plunger and spring, which pop out; owners do it in a bag and hold the plunger down with a card to refit the safety. (both)
  Owners report: Converting the P938 to a single side safety? - Topic — SIGforum sigforum.com [7] — “Do this in a ziplock bag, the safety detent plunger and spring will pop out.”
• The recoil spring and guide are under tension and loose in the slide. (disassembly)
  Source: P238 / P938 Operator's Manual (1202508-01 Rev03) — SIG SAUER, Inc. sigsauer.com [3] — “The recoil spring and guide are under spring tension and not firmly attached to the slide.”
• Worn mainspring housing detents let the mainspring migrate, so the hammer follows the slide; parts generation (housing, sear spring, hammer) has to match. (reassembly)
  Owners report: Mainspring housing and sear question, P938 - Topic — SIGforum sigforum.com [8] — “After my tear down inspection I have found the detent on my mainspring housing wearing and allowing my mainspring to migrate up.”

Fit or check on rebuild

• Safety detent plunger captured — If the plunger escapes the safety will not index
  Source: Converting the P938 to a single side safety? - Topic — SIGforum sigforum.com [7] — “using a thin piece of plastic or business card hold the detent plunger in place and turn the safety down into the safe position.”
• Hammer does not follow the slide — Worn MSH detent or mismatched sear spring/hammer generation lets the hammer follow
• Function check: trigger reset, sear/striker engagement, safeties — Standard post-reassembly check on any pistol whose fire-control parts were removed; a mis-seated spring shows up here, not on the bench

This is Pew-Takedown's rating, not the manufacturer's. How tiers are rated. Forum reports are owners' experience, not specifications.

Procedures

Torque specifications

No sourced torque values from the manufacturer are recorded for this firearm. Where a fastener has a specified torque — action screws, scope bases, muzzle devices, barrel nuts — get it from the manufacturer or a gunsmith rather than estimating it.

What the manufacturer does say: The manufacturer's documents give no torque value. They say: "Next, tighten each mounting screw until secure (60inch-ounces maximum). Do not over-tighten as this" (P238/P938 Laser Sight LIMA38 Owners Manual (7400927-01 R01), PDF p. 1 (installation step 5))

Reported by other sources — not the manufacturer

Materials and factory finish

As stated by SIG Sauer. Prep, masking and cure depend on these; a polymer or aluminium part, a nitrided or anodised finish, and a blued steel part are each a different job. Variants with other finishes may exist — check the maker's page for the exact SKU on the bench.

Parts list

Transcribed from the manufacturer's parts list (P238 / P938 Operator's Manual (1202508-01 Rev03) — SIG SAUER, Inc., p. 62–63 sigsauer.com [3]) — '13.3 Parts List' with '13.2 Parts Diagram' in the combined P238/P938 manual; it is the manual's only pistol parts list (not model-labelled), used for the P938. The .22LR conversion-kit lists (13.4, 13.5, p.64-65) were left out.. Key numbers refer to the exploded view in that document.

Function check

• Verify the pistol is unloaded with no magazine inserted before each check.
• Cock the hammer, engage the thumb safety, and press the trigger. The hammer must not fall.
• Disengage the safety and press the trigger. The hammer should fall.
• Hold the trigger back, rack the slide, release slowly and confirm the reset.
• Confirm the slide locks open on an empty magazine.
• Cycle dummy rounds by hand before carrying the pistol.

Maintenance

Lubrication points

• Frame rails where the slide rides
• Barrel hood and locking lug
• Outside of the barrel at the muzzle end
• Rear barrel lug where the recoil spring assembly bears

Cleaning notes

Light lubrication only — a thin film on the rails and barrel. Keep the striker or firing pin channel dry and free of solvent, since oil there collects fouling and causes light strikes. Clean carry pistols on a schedule rather than by round count.

Suggested inspection interval: roughly every 2000 rounds. This is a general guideline, not a manufacturer specification.

Wear parts to inspect

Recoil spring assembly (short springs wear faster) · Extractor · Magazine springs

Common issues

Also covers

The procedures above are reported to apply to: SIG P238 in .380 ACP · P938 Legion and SAS variants. Verify against the manual for your specific model.

Similar manual of arms

• SIG Sauer P365
• M1911A1 / 1911 Government Model

Sourcing